Wei-Jen Lee

University of Texas at Arlington | UTA · Department of Electrical Engineering

To combat climate change and global warming, the adoption of solar generation has increased remarkably. At the end of 2021, there was 92.5 GW of solar systems installed in the U.S. In California, 25% of electricity was generated from PV systems currently. However, due to the nature of inverter-based resources (IBRs), the inertia of power grids has...

Understanding the impact of wildfire smoke on photovoltaic (PV) systems is critical for the reliability and stability of power systems with the increasing PV penetration and wildfire events. However, this problem has not been widely discussed and studied in the existing literature. One of the significant challenges for this study is the quantificat...

With the development of mobility on-demand and transportation electrification technologies, electric vehicle (EV)-based ride-hailing fleets are playing an increasingly important role in the urban ground transportation system. Due to the stochastic nature of order request arrival and electricity price, there exists decision-making risks for ride-hai...

Over the next five years, the U.S. will deploy DC fast charging stations along its interstate highway system under the National Electric Vehicle Infrastructure (NEVI) formula program. The large-scale deployment of NEVI charging stations will significantly increase charging demand, posing challenges to power systems. Thus, understanding the charging...

With the high penetration of large-scale wind farms (WFs), accurate grid-connected WF models are crucial to be developed for studying the stability of power grids. Due to the large scale of the detailed model, a grid-connected WF is usually simplified into several aggregated wind turbine generators (WTGs) with the dynamic equivalent technique. Howe...

The gradually increased proportion of power electronic devices and the distributed energy resource (DER), in the distribution network, induced more harmonic and pulse signals to be injected into the grid. Arc faults, as the critical and common faults in the distribution system, are the potential reasons for the safety of the personnel and equipment...

Accurate and reliable electric arc fault identification ensures the safety of personnel and equipment through in-field operations and maintenance work. However, due to the application scenarios and nonlinear arc dynamics, the distortion degree of the detectable signals is influenced by network/circuit structure, system parameter, operation manner,...

Dissolved Gas Analysis (DGA) is an important method to identify internal faults of transformers. A novel predictive method for dissolved gas content in transformer oil based on temporal convolutional network (TCN) and graph convolutional network (GCN) is proposed in this paper. First, a Temporal Convolutional Network based on dilated causal convolu...

Load aggregators (LAs) gather regional demand response (DR) resources as a representative of regional users to transact with the grid. They achieve this by facilitating residential customers to flexibly participate in DR programs. This article proposes a residential DR strategic bidding approach for LAs to improve system reliability while maximizin...

The occurrence of electric arcs poses a huge threat to personal and equipment safety. As one of the effective ways to actively protect personnel and equipment away from serious arcing incidents, the signature recognition based arcing identification method has drawn much attention. However, since the strong nonlinear dynamics of the arcs, merely bas...

Periodical validation and calibration to microgrid models are necessary for investigating the behaviors of microgrids and evaluating the stability of connected power grids. However, instead of calibrating the problematic parameters that vary from their actual values, the commonly used methods normally adjust the selected sensitive parameters. The p...

In recent years, a large variety of short-term load forecasting methodologies have been proposed, but a common drawback of them is that require a large amount of historical data to train the model. However, in reality, the cases in limited historical data would be more frequently occurred, for example, a new house or substation is built. To tackle...

Battery swapping-charging systems (BSCSs) can provide better battery swapping services for electric vehicles (EVs) in large cities. In BSCSs, EV batteries can be centrally charged at battery charging stations (BCSs) and then dispatched via delivery trucks to battery swapping stations (BSSs) to support local EVs. This paper considers the real-time o...

With the advancement of transportation electrification and Internet of Things (IoT), the cloud based shared on-demand logistic fleet management platforms, such as Lalamove and Gogovan, become more and more popular. Under this setting, the scheduling platform needs to dispatch vehicles while dealing with the increasing charging demands of logistic f...

The autonomous mobility-on-demand (AMoD) system is regarded as a promising shared mobility method for the sustainable transportation system. In addition, battery swapping could become an efficient energy-refueling means for electric vehicles (EVs). The quality-of-service aware battery swapping price determined by the battery swapping stations (BSSs...

The dynamic line rating (DLR) can be an effective mechanism that reduces wind curtailment induced by line congestion considering its unique correlation to wind speed. However, the calculation of the DLR depends on accurate environmental parameters, which can be challenging in look-ahead decision-making applications. Consequently, transmission line...

The transmission-line fault localization of high-voltage (HV) transmission networks and different medium-voltage wind farms is implemented using a global time–frequency analysis algorithm, energy-spectrum-based hyperbolic S-transform (HS), to extract the potential power signatures from monitoring nonlinear and nonstationary fault signals on HV powe...

With the development of DC renewable power generation and DC power consumption, more and more attention has been paied on residential low voltage DC (RLVDC) power system in recent years, because of the advantages on conversion efficiency and control flexibility. Meanwhile, there are still some obstacles and challenges in practical implementation of...

Demand response (DR) is proven effective in reducing costs and increasing resilience for microgrids. In addition to fixed and un-adjustable public loads, loads that can participate in demand response are mainly divided into industrial, commercial, and residential loads. In many countries and regions, the electricity price and load baseline of these...

Challenged by urbanization and increasing travel needs, existing transportation systems call for new mobility paradigms. In this article, we present the fleet management and charging scheduling of a shared mobility-on-demand system, whereby electric vehicle fleets are operated by a centralized platform to provide customers with mobility service. We...

With the increasing penetrations of wind power in power systems, periodical calibration of the large-scale Wind Farm (WF) model is crucial to maintaining high-quality model performance for stability investigations. However, the existing calibration methods mainly focus on correcting synchronous generators, not the more dynamical WF model. Challenge...

The autonomous mobility-on-demand (AMoD) system plays an important role in the urban transportation system. The charging behavior of AMoD fleet becomes a critical link between charging system and transportation system. In this paper, we investigate a strategic charging pricing scheme for charging station operators (CSOs) based on a non-cooperative...

One major reliability concern regarding renewable energy resources connected in the vicinity of series-compensated power transmission lines or to weak power grids is sub-synchronous resonance (SSR). A particular type of interaction known as sub-synchronous control interaction (SSCI), with a purely electrical nature, has the potential to grow very r...

The power system industry often operates close to its limits to accommodate the increased demand, posing a high risk of blackouts. Power system restoration techniques are utilized post-breakout with the focus on load pickup and speedy recovery. In traditional heuristic methods, the load is considered to be constant after it is picked up. However, f...

Modern power systems are experiencing larger fluctuations and more uncertainties caused by increased penetration of renewable energy sources (RESs) and power electronics equipment. Therefore, fast and accurate corrective control actions in real time are needed to ensure the system security and economics. This paper presents a novel method to derive...

This paper introduces a new scheme for suburban renewable energies, hydrogen plant, and logistics (SRE-HP-LC) integration scheme and dispatching. The objective of the proposed SRE-HP-LC integration scheme aims at coordinating the operation of renewable energies, hydrogen production and storage and logistic transportation. In order to take advantage...

The autonomous mobility-on-demand (AMoD) system provides an alternative solution for sustainable and economical transportation system. Meanwhile, battery swapping could become a promising approach to sustain the efficient operation of EV fleet. This paper proposes a combined operation scheme for BSS and AMoD system. To maximizing the profit of AMoD...

Due to environmental concerns, renewable energy sources (RESs) gradually replace conventional power generations. In the last decade, wind and solar electricity generation have increased from 55 million MWh to 275 million MWh and from 2 million MWh to 96 Million MWh, respectively, in the US. Recently, FERC Order 2222 allows distributed energy resour...

Accurate model of generating unit plays a key role in power system modeling and simulation. To ensure the safe and stable operation of power grids, North American Electric Reliability Corporation (NERC) requires that all generators larger than 10 MVA have to perform the model verification in every five years. However, the traditional key parameter...

Considering the important role of energy in modern society, it is imperative to study the current situation and future development of energy under the influence of COVID-19. This paper identifies the current research hotspots, proposes future research directions accordingly, and summarizes the methodologies via a bibliometric analysis. Five researc...

Incentive-Based Demand Response (IBDR) was considered as a feasible option to solve the sudden shortage of Distributed Energy Resource (DER) in Microgrid. However, the current IBDR policies and strategies are not directly applicable to residents due to many defects. To this end, a versatile hierarchical IBDR strategy is proposed in this paper. To e...

With the emerging of prosumers in residential level, peer-to-peer (P2P) energy trading provide a novel way to prompt the localized management of distributed energy resources (DERs). However, the work of designing an appropriate market framework, with the fair and flexible pricing strategy for each participant, is still very challenging. This paper...

Accurate equivalent model can be efficiently to analyze the dynamic properties of Active Distribution Network (ADN) as well as assesse their impacts on stabilities of interconnected power system. However, due to stochastic nature of renewable resources and time-varying configurations of load conditions, traditional ADN equivalent model may not robu...

As power distribution systems become increasingly interconnected and concentrated with DER and high potential equipment, effectively avoid the medium-low voltage caused safety risk drawing more attentions. Therefore, the accurate, fast and reliable preemptive arc detection and location method is essentially to be developed. However, due to the issu...

In non-solidly earthed distribution networks, single-phase-to-ground faults (SPGFs) significantly threaten the safety of people and equipment. Although selection and location techniques for the existing fault lines have made remarkable contributions in reducing the damage due to SPGFs, a certain amount of power loss still exists in the SPGF owing t...

This article proposes a novel fault-localization method that is based on the nonintrusive fault-monitoring (NIFM) techniques in high-voltage/extra-high-voltage (HV/EHV) power transmission networks. In this work, the fault signals measured at the utilities are extracted by the hyperbolic S-transform (HST) before going through the identification proc...

With the increasing penetration of renewable energy, power grid operators are observing both fast and large fluctuations in power and voltage profiles on a daily basis. Fast and accurate control actions derived in real time are vital to ensure system security and economics. To this end, solving alternating current (AC) optimal power flow (OPF) with...

The interdependences between electric power systems and transportation systems are becoming increasingly tight as the market share of electric vehicles keeps booming. Therefore, improving the operation performance of power system and transportation system as an integrated system becomes a critical issue. This paper investigates the coordination bet...

This paper proposes a robust distributed secondary control approach for voltage restoration of an islanded microgrid with inverter-based distributed generators (DGs). In the proposed approach, each DG only requires the knowledge of its own and immediate neighboring information and dispenses with the need of complex communication network. Unlike mos...

With the emerging concept of sharing-economy, shared electric vehicles (EVs) are playing a more and more important role in future mobility-on-demand traffic system. This paper considers joint charging scheduling, order dispatching, and vehicle rebalancing for large-scale shared EV fleet operator. To maximize the welfare of fleet operator, we model...

This paper presents a spatial-temporal demand management scheme and cooperative benefit allocation method to optimize the operation of geo-distributed electric vehicle (EV) charging station and EV aggregators. Considering the spatial-temporal characteristics of EV charging demand and energy cost distribution, we first propose a collaborative demand...

The papers in this special issue focus on advanced approaches and applications for electric vehicle charging. Due to the concern of carbon emission, pollution, and oil depletion, transportation electrification has drawn more and more attention in both industrial and academic sectors. As one type of rapidly increasing power demands, electric vehicle...

The Single-phase-to-ground fault (SPGF) affects reliability and security of distribution system greatly. Accurate online recognition of fault causes can help improve the efficiency of weak components finding and maintenance. In this paper, various symptom features of the SPGF by typical causes are analyzed and a fuzzy inference system (FIS) for fau...

Arc flash hazard prediction methods have become more sophisticated because the knowledge about arc flash phenomenon has advanced since the publication of IEEE Std. 1584-2002[17]. The IEEE Std. 1584-2018 [13] has added parameters for more accurate arc flash incident energy, arcing current and protection boundary estimation. The parameters in the upd...

To improve the comprehensive performance of the metro traction power supply system (MTPSS), a new multi-pulse integrated metro traction power supply system (MI-MTPSS) is proposed in this paper. The configuration and characteristics of MI-MTPSS are introduced, and based on the practical bilateral-ring power supply structure, a series of MTPSS-combin...

The existence of wake effect can affect the total power generation of a wind farm. To alleviate the impact of wake effect, numerous algorithms under the paradigm of evolutionary computation have been proposed to find the optimal layout of wind turbines. Previously, inspired by the self-adjustment capability among the individuals of a species in the...

A contactless method based on infrared image matching is presented for zero-value insulator detection on outdoor porcelain insulator string. An improved SIFT (scale-invariant feature transformation) method is developed to extract features and accomplish the pre-matching between the insulator string to be detected and the standard string in the imag...

Regional wind power forecasting is conducive to achieving scientific dispatch of the power system as well as improving its reliability. Data mining based on a large number of samples is an effective way to improve the accuracy of wind power forecasting. A new regional power forecasting method in the context of data mining is presented in this paper...

Solving AC optimal power flow (OPF) with operational security constraints remains an important but challenging optimization problem for secure and economic operations of the power grid. With the ever-increasing penetration of renewable energy, fast and large fluctuations in power and voltage profiles are observed on a daily basis; thus, fast and ac...

Due to the geographic features and fruitful water resources, the distributed generation of Small Hydropower Generator Stack (SHGS) are vigorously developed in southwest China. As the more concerns about security and stability of power grids with the large amount of SHGS feed into the grid, the accurate models are critical to analyze those potential...

Due to the maturity of wide area measurement technology, phasor measurement unit (PMU)-based dynamic equivalent modeling method (PDM) has been wildly used in large-scale power system modeling. However, traditional “event-based” PDM equivalent model may face serious robustness issues, such as although derived equivalent models show the good ability...

With more distributed energy resources penetrated into the residential community, nanogrid based peer-to-peer (P2P) energy market has rapidly emerged over recent years. Due to the complexities on the decision-making process of each market participant, an efficient, fair and beneficial oriented bidding strategy is thus necessary. In this article, a...

Unlike short circuit faults in power systems, arcing faults produce intense light during fault events. Light-sensing technology has been under development to detect arc faults since the 1980s. Currently, optical fiber and point sensors are two types of light sensors applied, along with the simultaneous overcurrent mechanism, for arc-flash relays. D...

Frequency scanning is a powerful and versatile approach for Sub-Synchronous Resonance (SSR) screening in power grids. Among different numerical and analytical frequency scanning techniques, the harmonic injection method is well suited for the scan of black-box models with active elements, such as in wind farms and solar plants. The results can be u...

Power grids have recently become more susceptible to Sub-Synchronous Control Interactions (SSCI) due to the increasing penetration of renewable resources and series-compensated lines. SSCI is a purely electrical and fast-growing phenomenon. Therefore, without an expeditious detection and mitigation solution, it can cause serious damage to renewable...

The uncertainty of power system is intensified by the integration of large-scale renewable energy resources such as wind farm (WF). Considering the impact of system uncertainties, the probabilistic stability analysis methods have been used in the stability assessments of power system with the WF integration. However, in traditional probabilistic an...

Electronic current transducers based on Rogowski coil are commonly used for power system protection. However, they may generate additional dynamic components in some cases that may cause misoperation of protection devices. In order to check the hidden danger of this undesired phenomenon, this paper studies the transfer characteristics of Rogowski c...

This research describes a real-time optimization model for multi-agent demand response (DR) from a Load Serving Entity (LSE) perspective. Three major categories of customers and five types of energy resources are considered simultaneously to achieve efficient DR decision making in highly stochastic future energy markets. Two infinite horizon stocha...

As one of the most promising renewable energy resources, a large amount of wind energy has been implemented all around the world since 1990s. Increasing the size of the wind turbines and the harsh operating environment lead to higher failure rates on the wind turbines compared with other renewable resources. As the result, not only unplanned mainte...

In arc flash hazards calculations, protection boundary can be used to gain insight in personnel protection against thermal injuries. Although IEEE 1584-2002 has provided the calculation guide based on tests with the arcing electrodes in a vertical plane, applications where the traditional vertical arrangement is not directly applicable is drawing m...